Residential fireplace insert

ABSTRACT

An improvement in the art relates to an insert fitted into a standard residential fireplace opening for burning fossel fuels such as wood or coal.

BACKGROUND

For many years a standard masonry fireplace cavity whether of brick stone, or other non-flammable materials usually required dimensions of 35″ wide, 30″ high, 22″ deep, and a rear dimension of 24″ width. Early fireplaces had no doors and were “open” but would eventually accommodate a screen for fire prevention from flying sparks. Earlier colonial era fireplaces of two centuries ago included a one or two level height of stone or brick on the hearth on each side called hobs. These hobs provided the dual function of a warming shelf and confining the draft of air more efficiently to the burning area flame by “closing-in” the space between the ends of the logs and the fireplace sides. In more modern days an enclosure was employed utilizing himged glass doors to allow replenishment of fuel for combustion. Thus, draft control consisted of minimal damper adjustment to control heat radiation and the hobs helped to direct draft air more effectively to the flame area. In recent years we have had a resurgent interest in obtaining better fireplace inserts, many looking like a smaller “Franklin-Type” design; an iron-sided heatradiatimg, free-standing box with draft control doors.

SUMMARY

My improvement in the art relates to an insert fitted into a standard residential fireplace opening burning fossel fuels such as wood or coal. This insert is simply a box structure loosely formed of metal pipes (or tubings) and using one or more plenum chambers (in the hobs location) supplying air under light air pressure to be heated within the said tubing arrangement of pipes rising up the right and left sides within the fireplace cavity. Said arrangements converges across the top of the fireplace cavity proceeds down the back of the fireplace cavity and is directed forwardly in a horizontal fashion over a fragrance strip into the attendant room from the fireplace cavity using exit openings on an intermediate level between the heat-radiating woven or iron grate level above, and the ash collector pan level beneath. Included also are major and minor draft adjustments, plus intake axial fan speed controls.

An unexpected benefit is realized when the fire is “low” and only glowing coals are left: when adding new wood fuel on top of the glowing coals, just raising the major draft door slightly catches part of the exiting air flow redirecting it back through the mesh grate thereby fanning the embers “into life” easily igniting the newly added fuel.

An optional further improvement in the art also utilizes a specially configured electrical heating rod (eg.“Calrod” or equiv.) fashioned as to be inserted into the said horizontal forwardly disposed exiting pipes and able to supply heat into the attendant room even when no flame-type ongoing heat radiating source through the woven wire mesh or cast grate is utilized.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is a top view of the fireplace insert also showing an electrical outlet receptacle to power an “inside” artificial flame display, and a fragerance strip location.

FIG. 2 is a right quarter rear view in perspective showing general pipe installation detail and said receptacle.

FIG. 3 shows the general configuration of the serpentine optional electric heating rod design arrangement and disposition 21 prior to insertion in the forwardly disposed horizontal exiting heat pipes: another usual electric heating rod design is the “ladder” design arrangement (not shown). The said woven wire screen (or metal grate 22), plus the consumable fuel rests upon the said exiting air heating pipes.

FIGS. 4 and 5 show the general disposition of a draft control door 16, hinged on the near (lower) edge, smaller manual draft adjustment 17, plenum chambers (hobs) fans 11 and control 18, heater rod control 19, and ash collector pan 20. Also shown is the fireplace enclosure frame 14 and glass doors 15.

As illustrated in the drawing, FIGS. 1, 2, 4, and 5 show the plenum chambers 10, with axial air intake fans 11, supplying air being heated through one or more circular (or any shaped) pipes or tubings 12, rising from the said plenum chambers up the right and left sides of the fireplace cavity, converging across the top of the said fireplace cavity, directed down the rear surface of the said fireplace cavity, and redirected forwardly into the attending room over a fragrance strip 24 in a generally horizontal plane from the said fireplace cavity through one or more air outlets 13. Also shown is electrical outlet 23. 

1. An improvement in the art relating to a residential fireplace insert fitted into a standard fireplace cavity. The insert is simply a box structure (plus front enclosure) loosely formed of metal pipes (or tubings) and using one or more plenum chambers (hobs) with suction fan(s). The fans supply air under pressure to be heated while rising up the right and left sides of the said fireplace cavity through one or more circular or otherwise shaped heating tubes. The tubes converging across the top of the said fireplace cavity, proceed down the rear of the said fireplace cavity and are directed forwardly into the attendant room from near the bottom of the said fireplace cavity using natural radient heat (and/or supplimental electric heat). The exit openings can be located between the heat-providing iron or wire screen grate level above and the ash collector pan level beneath. Said fireplace insert incorporates all related draft, fan, and heat-regulating controls. 